They won t be appropriate for all roofs.
Roof asphalt shingles requirements.
They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.
Fasteners for asphalt shingles shall be galvanized stainless steel aluminum or copper roofing nails minimum 12 gage 0 105 inch 2 67 mm shank with a minimum 0 375 inch diameter 9 5 mm head of a length to penetrate through the roofing materials and a minimum of 0 75 inch 19 1 mm thick the nails shall penetrate through the sheathing.
There are two simple rules to follow.
The slope of the roof is measured by the vertical rise of the roof to the horizontal run and is expressed as a fraction.
Below 40 f shingles are brittle and crack easily when hammered or bent.
Fortunately the requirements are quite accommodating.
Each flashing should overlap the one below by at least 75 mm 3 but not be visible below the shingle top lap.
Asphalt shingles do require that you have a minimum pitch to your roof.
Imbed each step flashing in a 75 mm 3 wide application of asphaltic plastic cement and nail in place.
A 4 12 roof slope means the roof rises 4 feet for every 12 feet of horizontal roof span.
Installation temperature requirements for asphalt shingle roofs ideally shingles should be installed at temperatures ranging from 40 f to 85 f.
The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.
Asphalt shingles can only be used on roof slopes of two units vertical in 12 units horizontal 2 12 or greater.